The patch titled
Subject: arch, mm: restore dependency of __kernel_map_pages() of DEBUG_PAGEALLOC
has been added to the -mm tree. Its filename is
arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc.patch
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The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Subject: arch, mm: restore dependency of __kernel_map_pages() of DEBUG_PAGEALLOC
The design of DEBUG_PAGEALLOC presumes that __kernel_map_pages() must
never fail. With this assumption is wouldn't be safe to allow general
usage of this function.
Moreover, some architectures that implement __kernel_map_pages() have this
function guarded by #ifdef DEBUG_PAGEALLOC and some refuse to map/unmap
pages when page allocation debugging is disabled at runtime.
As all the users of __kernel_map_pages() were converted to use
debug_pagealloc_map_pages() it is safe to make it available only when
DEBUG_PAGEALLOC is set.
Link: https://lkml.kernel.org/r/20201103162057.22916-4-rppt@xxxxxxxxxx
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: "Edgecombe, Rick P" <rick.p.edgecombe@xxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Len Brown <len.brown@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/Kconfig | 3 +++
arch/arm64/Kconfig | 4 +---
arch/arm64/mm/pageattr.c | 8 ++++++--
arch/powerpc/Kconfig | 5 +----
arch/riscv/Kconfig | 4 +---
arch/riscv/include/asm/pgtable.h | 2 --
arch/riscv/mm/pageattr.c | 2 ++
arch/s390/Kconfig | 4 +---
arch/sparc/Kconfig | 4 +---
arch/x86/Kconfig | 4 +---
arch/x86/mm/pat/set_memory.c | 2 ++
include/linux/mm.h | 10 +++++++---
12 files changed, 26 insertions(+), 26 deletions(-)
--- a/arch/arm64/Kconfig~arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc
+++ a/arch/arm64/Kconfig
@@ -71,6 +71,7 @@ config ARM64
select ARCH_USE_QUEUED_RWLOCKS
select ARCH_USE_QUEUED_SPINLOCKS
select ARCH_USE_SYM_ANNOTATIONS
+ select ARCH_SUPPORTS_DEBUG_PAGEALLOC
select ARCH_SUPPORTS_MEMORY_FAILURE
select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
select ARCH_SUPPORTS_ATOMIC_RMW
@@ -1026,9 +1027,6 @@ config HOLES_IN_ZONE
source "kernel/Kconfig.hz"
-config ARCH_SUPPORTS_DEBUG_PAGEALLOC
- def_bool y
-
config ARCH_SPARSEMEM_ENABLE
def_bool y
select SPARSEMEM_VMEMMAP_ENABLE
--- a/arch/arm64/mm/pageattr.c~arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc
+++ a/arch/arm64/mm/pageattr.c
@@ -155,7 +155,7 @@ int set_direct_map_invalid_noflush(struc
.clear_mask = __pgprot(PTE_VALID),
};
- if (!rodata_full)
+ if (!debug_pagealloc_enabled() && !rodata_full)
return 0;
return apply_to_page_range(&init_mm,
@@ -170,7 +170,7 @@ int set_direct_map_default_noflush(struc
.clear_mask = __pgprot(PTE_RDONLY),
};
- if (!rodata_full)
+ if (!debug_pagealloc_enabled() && !rodata_full)
return 0;
return apply_to_page_range(&init_mm,
@@ -178,6 +178,7 @@ int set_direct_map_default_noflush(struc
PAGE_SIZE, change_page_range, &data);
}
+#ifdef CONFIG_DEBUG_PAGEALLOC
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
if (!debug_pagealloc_enabled() && !rodata_full)
@@ -186,6 +187,7 @@ void __kernel_map_pages(struct page *pag
set_memory_valid((unsigned long)page_address(page), numpages, enable);
}
+#ifdef CONFIG_HIBERNATION
/*
* This function is used to determine if a linear map page has been marked as
* not-valid. Walk the page table and check the PTE_VALID bit. This is based
@@ -232,3 +234,5 @@ bool kernel_page_present(struct page *pa
ptep = pte_offset_kernel(pmdp, addr);
return pte_valid(READ_ONCE(*ptep));
}
+#endif /* CONFIG_HIBERNATION */
+#endif /* CONFIG_DEBUG_PAGEALLOC */
--- a/arch/Kconfig~arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc
+++ a/arch/Kconfig
@@ -1035,6 +1035,9 @@ config HAVE_STATIC_CALL_INLINE
bool
depends on HAVE_STATIC_CALL
+config ARCH_SUPPORTS_DEBUG_PAGEALLOC
+ bool
+
source "kernel/gcov/Kconfig"
source "scripts/gcc-plugins/Kconfig"
--- a/arch/powerpc/Kconfig~arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc
+++ a/arch/powerpc/Kconfig
@@ -146,6 +146,7 @@ config PPC
select ARCH_MIGHT_HAVE_PC_SERIO
select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
select ARCH_SUPPORTS_ATOMIC_RMW
+ select ARCH_SUPPORTS_DEBUG_PAGEALLOC if PPC32 || PPC_BOOK3S_64
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_CMPXCHG_LOCKREF if PPC64
select ARCH_USE_QUEUED_RWLOCKS if PPC_QUEUED_SPINLOCKS
@@ -355,10 +356,6 @@ config PPC_OF_PLATFORM_PCI
depends on PCI
depends on PPC64 # not supported on 32 bits yet
-config ARCH_SUPPORTS_DEBUG_PAGEALLOC
- depends on PPC32 || PPC_BOOK3S_64
- def_bool y
-
config ARCH_SUPPORTS_UPROBES
def_bool y
--- a/arch/riscv/include/asm/pgtable.h~arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc
+++ a/arch/riscv/include/asm/pgtable.h
@@ -461,8 +461,6 @@ static inline int ptep_clear_flush_young
#define VMALLOC_START 0
#define VMALLOC_END TASK_SIZE
-static inline void __kernel_map_pages(struct page *page, int numpages, int enable) {}
-
#endif /* !CONFIG_MMU */
#define kern_addr_valid(addr) (1) /* FIXME */
--- a/arch/riscv/Kconfig~arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc
+++ a/arch/riscv/Kconfig
@@ -14,6 +14,7 @@ config RISCV
def_bool y
select ARCH_CLOCKSOURCE_INIT
select ARCH_SUPPORTS_ATOMIC_RMW
+ select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
select ARCH_HAS_BINFMT_FLAT
select ARCH_HAS_DEBUG_VM_PGTABLE
select ARCH_HAS_DEBUG_VIRTUAL if MMU
@@ -153,9 +154,6 @@ config ARCH_SELECT_MEMORY_MODEL
config ARCH_WANT_GENERAL_HUGETLB
def_bool y
-config ARCH_SUPPORTS_DEBUG_PAGEALLOC
- def_bool y
-
config SYS_SUPPORTS_HUGETLBFS
depends on MMU
def_bool y
--- a/arch/riscv/mm/pageattr.c~arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc
+++ a/arch/riscv/mm/pageattr.c
@@ -184,6 +184,7 @@ int set_direct_map_default_noflush(struc
return ret;
}
+#ifdef CONFIG_DEBUG_PAGEALLOC
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
if (!debug_pagealloc_enabled())
@@ -196,3 +197,4 @@ void __kernel_map_pages(struct page *pag
__set_memory((unsigned long)page_address(page), numpages,
__pgprot(0), __pgprot(_PAGE_PRESENT));
}
+#endif
--- a/arch/s390/Kconfig~arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc
+++ a/arch/s390/Kconfig
@@ -35,9 +35,6 @@ config GENERIC_LOCKBREAK
config PGSTE
def_bool y if KVM
-config ARCH_SUPPORTS_DEBUG_PAGEALLOC
- def_bool y
-
config AUDIT_ARCH
def_bool y
@@ -106,6 +103,7 @@ config S390
select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
select ARCH_STACKWALK
select ARCH_SUPPORTS_ATOMIC_RMW
+ select ARCH_SUPPORTS_DEBUG_PAGEALLOC
select ARCH_SUPPORTS_NUMA_BALANCING
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_CMPXCHG_LOCKREF
--- a/arch/sparc/Kconfig~arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc
+++ a/arch/sparc/Kconfig
@@ -88,6 +88,7 @@ config SPARC64
select HAVE_C_RECORDMCOUNT
select HAVE_ARCH_AUDITSYSCALL
select ARCH_SUPPORTS_ATOMIC_RMW
+ select ARCH_SUPPORTS_DEBUG_PAGEALLOC
select HAVE_NMI
select HAVE_REGS_AND_STACK_ACCESS_API
select ARCH_USE_QUEUED_RWLOCKS
@@ -148,9 +149,6 @@ config GENERIC_ISA_DMA
bool
default y if SPARC32
-config ARCH_SUPPORTS_DEBUG_PAGEALLOC
- def_bool y if SPARC64
-
config PGTABLE_LEVELS
default 4 if 64BIT
default 3
--- a/arch/x86/Kconfig~arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc
+++ a/arch/x86/Kconfig
@@ -91,6 +91,7 @@ config X86
select ARCH_STACKWALK
select ARCH_SUPPORTS_ACPI
select ARCH_SUPPORTS_ATOMIC_RMW
+ select ARCH_SUPPORTS_DEBUG_PAGEALLOC
select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_QUEUED_RWLOCKS
@@ -330,9 +331,6 @@ config ZONE_DMA32
config AUDIT_ARCH
def_bool y if X86_64
-config ARCH_SUPPORTS_DEBUG_PAGEALLOC
- def_bool y
-
config KASAN_SHADOW_OFFSET
hex
depends on KASAN
--- a/arch/x86/mm/pat/set_memory.c~arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc
+++ a/arch/x86/mm/pat/set_memory.c
@@ -2194,6 +2194,7 @@ int set_direct_map_default_noflush(struc
return __set_pages_p(page, 1);
}
+#ifdef CONFIG_DEBUG_PAGEALLOC
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
if (PageHighMem(page))
@@ -2239,6 +2240,7 @@ bool kernel_page_present(struct page *pa
return (pte_val(*pte) & _PAGE_PRESENT);
}
#endif /* CONFIG_HIBERNATION */
+#endif /* CONFIG_DEBUG_PAGEALLOC */
int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address,
unsigned numpages, unsigned long page_flags)
--- a/include/linux/mm.h~arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc
+++ a/include/linux/mm.h
@@ -2912,7 +2912,11 @@ static inline bool debug_pagealloc_enabl
return static_branch_unlikely(&_debug_pagealloc_enabled);
}
-#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP)
+#ifdef CONFIG_DEBUG_PAGEALLOC
+/*
+ * To support DEBUG_PAGEALLOC architecture must ensure that
+ * __kernel_map_pages() never fails
+ */
extern void __kernel_map_pages(struct page *page, int numpages, int enable);
static inline void debug_pagealloc_map_pages(struct page *page,
@@ -2925,13 +2929,13 @@ static inline void debug_pagealloc_map_p
#ifdef CONFIG_HIBERNATION
extern bool kernel_page_present(struct page *page);
#endif /* CONFIG_HIBERNATION */
-#else /* CONFIG_DEBUG_PAGEALLOC || CONFIG_ARCH_HAS_SET_DIRECT_MAP */
+#else /* CONFIG_DEBUG_PAGEALLOC */
static inline void debug_pagealloc_map_pages(struct page *page,
int numpages, int enable) {}
#ifdef CONFIG_HIBERNATION
static inline bool kernel_page_present(struct page *page) { return true; }
#endif /* CONFIG_HIBERNATION */
-#endif /* CONFIG_DEBUG_PAGEALLOC || CONFIG_ARCH_HAS_SET_DIRECT_MAP */
+#endif /* CONFIG_DEBUG_PAGEALLOC */
#ifdef __HAVE_ARCH_GATE_AREA
extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm);
_
Patches currently in -mm which might be from rppt@xxxxxxxxxxxxx are
mm-introduce-debug_pagealloc_map_pages-helper.patch
pm-hibernate-make-direct-map-manipulations-more-explicit.patch
arch-mm-restore-dependency-of-__kernel_map_pages-of-debug_pagealloc.patch
arch-mm-make-kernel_page_present-always-available.patch
